Device for cutting antenna wire



June 13, 1933- c M 1 1,913,813

DEVICE FOR CUTTING ANTENNA WIRE Filed July 30, 1929 I 2 Sheets-Sheet l June 13, 1933- c. B. MIRICK DEVICE FOR CUTTING ANTENNA WIRE Filed July 30, 1929 2 Sheets-Sheet 2 Patented June 13, 1933 UNITED STATES PATENT OFFICE CARLOS B. MIRICK, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO NATIONAL ELECTRICAL SUPPLY COMPANY, OF WASHINGTON, DISTRICT OF COLUMBIA, A COR- PORATION OI VIRGINIA DEVICE FOR CUTTING ANTENNA WIRE Application filed July 30, 1929.- Serial No. 382,233.

My' invention relates broadly to aircraft radio communication systems and more particularly to an antenna lead-in attachment for aircraft.

One of the objects of my invention is to provide an attachment for aircraft having means for guiding a trailing wire antenna free of the aircraft to a position where proper operation of radio communication apparatus on the aircraft may be obtained.

Another object of my invention is to provide an attachment for installation upon aircraft where a trailing wire antenna is employed with means for cutting away the antenna wire under conditions of emergency to prevent entanglement of the wire with the aircraft, and particularly guarding against accident which might arise by the antenna striking the propeller, fouling controls or injuring personnel.

Still another object of my invention is to provide a construction of severing device for a trailing wire antenna on aircraft, which device may be brought into immediate operation in the event of accident to cut away the extended antenna under emergency conditions where it may be necessary to make a forced landing and avoid entanglement of the antenna with parts of the aircraft.

A further object of my invention is to provide an antenna lead-in insulator for aircraft with an attachment for the lead-in insulator in the form of an anvil and cutting tool by which the antenna wire may be snapped and cut away under emergency conditions on aircraft to avoid danger of entanglement of the antenna with parts of the aircraft.

Other and further objects of my invention reside in the construction of antenna severing device as set forth more particularly in the specification hereinafter following by reference to the accompanying drawings, in which:

Figure 1 illustrates the attachment of my invention installed on an aircraft; Fig. 2 is a front view of the antenna lead-in insulator on aircraft with the attachment of my invention secured in place thereon; Fig. 3 is a side elevation of the antenna lead-in insulator equipped with the attachment of my inshowing the attachment means forthe severing device of my invention; Fig. 6 is a longitudinal cross-sectional View through the attachment of my invention and Fig. 7 is a fragmentary view showing the upper extremity of the lead-in insulator to which the attachment of my invention may be applied or removed.

My invention is directed to an attachment for aircraft where a trailing wire antenna is employed in connection with the radio communication apparatus on aircraft. The antenna wire is unwound from an antenna reel and caused. to hang below and behind the plane by means of a weight or fish attached to the end of the wire. allowed to pass out'of the hull of the plane through an insulated tube. The antenna weightis approximately one-half inch in diameter and the lead-out tube is made large enough so that in case an antenna is lost a new weight and wire can be dropped through the tube from the inside of the hull, thus permitt-ing the renewal of radio communication aboard the plane. Before making a landing it is necessary to windin this trailing wire. Otherwise, it may bounce after striking the ground or water as the plane comes down, and may cause serious accident by striking propeller, fouling controls or injuring personnel. It sometimes happens that in making a forced landing there is not time to do this and it is then necessary to cut the wire, but the necessary cutting pliers are seldom available. The purpose of my invention is to provide a cutting device inherent in the lead-out fitting so that it will always be ready in an emergency.

Referring more particularly to the drawings, reference character 1 designates an air-' This wire is as shown at a extends beneath the hull for sufficient distance to guide the antenna wire clear of all parts of the plane. The insulated tube at terminates in an end flange 5 secured by rivets 5a to the interior cylindrical portion 56 of the member 5 as shown. The upper end of the insulated tube 2 is provided with diametrically opposite pins 2a and 2b which are arranged to enter bayonet grooves 16 and 17 within the bell fitting 11.

The bell fitting 11 is shaped as shown at 12 to permit the passage of the antennna wire 6 from the antenna reel 8 into the lead-out insulator 2 through the aperture 15 formed in the bell fitting. The bell fitting 11 is slotted laterally as shown at 14 to receive the sliding member 25 which may be reciprocated therein under control of manually operated lever mechanism having hand grip 29. The slide 25 is apertured at 36 to grip with the aperture 15 which is directly beneath the bell shaped head 12. Normally the antenna wire passes directly through the aperture 36 in slide 25 and through the tube 24 and trails below and behind the aircraft as designated at 6 in Fig. 1, under control of the weight 7. The hand lift 29 is pivoted at 20 between members 19 by means of a pin which passes through members 19 and the portion 21 of the hand lever. The upper portion of the hand lever is shown at 23 having an elongated aperture therein through which there is passed a pin 24 which extends through arms 22 formed integral with the slide 25. In order to maintain the hand lever 29 in a normal position such as shown in Fig. 3, I provide a band member 26 which encircles the bell 11 in a groove adjacent the lower extremity of the bell and terminates in spring jaws 28 which grip opposite sides of grooves 27 in the hand lever.

In leading out the antenna the bell fitting 11 is removed from the end of the tube 2. I provide sufficient clearance at 18 to permit ready removal and replacement of the fitting 11. The diameter of tube 2 is such that the antenna wire may be threaded through the bell fitting 11, through the aperture 36 in slide 25, the weight or fish attached and then the weight or fish with the antenna wire attached dropped through the tube 2. The bell fitting 11 may now be secured in position over the end of tube 2 by moving the bell fitting pins 2a and 2b guided by grooves 16 and 17 The antenna wire may then be let down by revolving antenna reel 8 by hand knob 9 so that the antenna wire 6 assumes the position shown in Fig. 1 and may thereafter be extended to the desired limit for required operation of the radio communication apparatus aboard the aircraft.

The top and bottom walls of the slot 14 adjacent the aperture 15 in the bell fitting 11 serve as anvils or cutting jaws with which the faces of slide 25 cooperate when aperture 36 is brought adjacent aperture 15. The antenna wire 6 passes through aperture 36 and 15 and when it is desired to cut the wire in an emergency it is only necessary to pull lever 29 which moves slide 25 bringing about a cutting action between the edges of aperture 36 and the anvil edges of aperture 15 both above and below the slide 25 thereby pinching off the wire which gravitates through the tube 2, avoiding any possibility of fouling or entanglement with the controls or propeller.

The fitting of my invention has been found to be extremely practical in its construction and successful in operation and adds a considerable measure of safety in aircraft operation avoiding the danger of accidents which arise by the entanglement of the antenna wire with parts of the machine.

Vhile I have described my invention in one of its preferred embodiments I desire that it be understood that modifications may be made and that no limitations upon my invention are intended other than. are imposed by the scope of the appended claims.

WVhat I claim as new and desire to secure by Letters Patent of the United States is as follows:

1. In a device of the character described. a tubular insulator open at its ends and adapted to be supported in a vertical position through a flooring with a portion projecting upwardly therefrom, a head for the upper end of said insulator formed with an axially extending passage of sufiicient diameter to permit passage of an antenna wire and its weight ('lownwardly through the head and insulator, said head being formed with a transverse slot intersecting the wire passage and being of greater width than the diameter of the passage and projecting from opposite sides thereof, a cutter bar slidable longitudinally in said slot with one end projecting from the slot, said bar being formed with an opening normally registering with the passage to permit uninterrupted passage of the antenna wire through the head and cutter bar, and means connected with the outer end of said cutter bar for normally retaining the cutter bar in a set position with its open ing registering with the passage of the head constituting an actuatin element for imparting longitudinal movement to the cutter bar and causing an antenna wire to be severed by shearing action of margins of the passage and opening.

2. In a device of the character described, a tubular insulator open at its ends and adapted to be supported in a vertical position through a flooring with a portion projecting upwardly therefrom, a head for the upper end of said insulator formed with an axially extending passage of sufficient diameter to permit passage of an antenna Wire and its weight downwardly through the head and insulator, said head being formed with a transverse slot intersecting the wire passage and being of greater width than the diameter of the passage and projecting from opposite sides thereof, a cutter bar slidable longitudinally in said slot with one end projecting from the slot, said bar being formed with an opening normally registering with the passage to permit uninterrupted passage of the antenna wire through the head and cutter bar, a lever pivotally connected with said head and normally disposed vertically close to the head and insulator, said lever having one end pivotally connected to the outer end of said cutter bar and its other end formed. with a hand hold whereby it may be readily grasped and swung about its pivot to impart longitudinal movement to the cutter bar and cause an antenna wire'to be severed by shearing action of margins of the passage and opening, and means carried by said head to engage a portion of said lever and releasably hold the same in its normal position with the opening of the cutter bar registering with. the passage of the head.

CARLOS B. MIRICK. 

